Open Radar

 
Summary:
When reading a JSON feed from a remote server, and serializing the data to a dictionary, and printing the result shows the lower ~10 bits of the scalar type set to 0, thus resulting in data loss when printing out the integer.

Steps to Reproduce:
1. Run the attached test case

Expected Results:
I would expect to see printed:

6988047877858960833 6988047877858960833

Actual Results:
I see printed:

6988047877858960833 6988047877858960384

Version:
iOS 7.0.3/iPhone 5

Notes:
Parsing the NSNumber is sufficient to reveal this bug.

Configuration:
Occurs on iOS 7, on iPhone 5 & 5S as well as in 32-bit and 64-bit simulators.

Attachments:
'nsnumber-corruption.m' was successfully uploaded.

#import <Foundation/Foundation.h>

int main(void)
{
    @autoreleasepool {
        NSDictionary *json = [NSJSONSerialization JSONObjectWithData:[@"{\"id\":6988047877858960833}" dataUsingEncoding:NSUTF8StringEncoding] options:0 error:NULL];
        NSLog(@"%@ %llu", json[@"id"], [json[@"id"] unsignedLongLongValue]);
    }
    return 0;
}